This invention concerns a work light for construction purposes, and is in the form of a string of lights that is hung in a work area, typically in a building under construction, to illuminate the work space.
Currently, what is commonly used for construction lighting is a string of incandescent lamps, each of which is contained in a plastic safety cage. This arrangement using incandescent lamps has a number of limitations. First, fourteen-gauge wire cable is the largest that can be used, because larger cable, such as twelve-gauge, becomes too stiff for the workmen to move it from place to place. However, 14-gauge wire limits the total current through the wires to about 15 amps, for safety purposes. This means there is a limit of fifteen one-hundred watt lamps that can be used on a single string. Also, the incandescent lamps have to be protected, and OSHA requires that a safety cage (plastic) be placed over each lamp. Even so, these often fall off during the workday, leaving a bulb uncovered. The incandescent lamps will fail if dropped, even if protected by a cage, because the filament breaks. Even under the most ideal conditions, the lamps last only a few hundred hours, so bulb replacement is a continuing problem, often requiring the workman to climb up a ladder to replace the lamp.
There have been several worklights proposed previously, which incorporate fluorescent lamps. Bowen U.S. Pat. No. 5,493,482 involves a multiple-tube arrangement encased within a tubular case or shell, and where there is a female power receptacle provided so that a number of these can be strung together. Grooms et al. U.S. Pat. No. 5,436,815 relates to a utility light that incorporates a U-shaped fluorescent tube. Burke U.S. Pat. No. 4,658,337 and Hocheim et al. U.S. Pat. No. 5,132,885 relate to portable fluorescent lighting devices, which incorporate straight fluorescent tubes. None of these prior approaches has considered using compact fluorescent lamps to overcome the drawbacks of the conventional (i.e., incandescent) worklight strings, as discussed above.